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[PATCH] __get_page_state() cpumask cleanup and fix
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__get_page_state() has an open-coded for_each_cpu_mask() loop in it.

Tidy that up, then notice that the code was buggy:

	while (cpu < NR_CPUS) {
		unsigned long *in, *out, off;

		if (!cpu_isset(cpu, *cpumask))
			continue;

an obvious infinite loop.  I guess we just never call it with a holey cpu
mask.

Even after my cpumask size-reduction work, this patch increases code size :(

Cc: Paul Jackson <pj@sgi.com>
Cc: Christoph Lameter <clameter@engr.sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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Andrew Morton authored and Linus Torvalds committed Mar 22, 2006
1 parent 68ed004 commit b40607f
Showing 1 changed file with 9 additions and 11 deletions.
20 changes: 9 additions & 11 deletions mm/page_alloc.c
Original file line number Diff line number Diff line change
Expand Up @@ -1214,24 +1214,22 @@ DEFINE_PER_CPU(long, nr_pagecache_local) = 0;

static void __get_page_state(struct page_state *ret, int nr, cpumask_t *cpumask)
{
int cpu = 0;
unsigned cpu;

memset(ret, 0, nr * sizeof(unsigned long));
cpus_and(*cpumask, *cpumask, cpu_online_map);

cpu = first_cpu(*cpumask);
while (cpu < NR_CPUS) {
unsigned long *in, *out, off;

if (!cpu_isset(cpu, *cpumask))
continue;
for_each_cpu_mask(cpu, *cpumask) {
unsigned long *in;
unsigned long *out;
unsigned off;
unsigned next_cpu;

in = (unsigned long *)&per_cpu(page_states, cpu);

cpu = next_cpu(cpu, *cpumask);

if (likely(cpu < NR_CPUS))
prefetch(&per_cpu(page_states, cpu));
next_cpu = next_cpu(cpu, *cpumask);
if (likely(next_cpu < NR_CPUS))
prefetch(&per_cpu(page_states, next_cpu));

out = (unsigned long *)ret;
for (off = 0; off < nr; off++)
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